高温下不同银含量微电子胶连点的力学性能及膨胀系数不匹配热应力

摘要

采用热机械分析仪和微压入测试系统对不同银含量微电子互连导电胶进行测试表征,并基于数值模拟分析其用于倒装芯片封装时胶层的不匹配热应力.结果表明,较高银含量固化导电胶的玻璃化转变温度滞后于较低银含量固化导电胶,且其热膨胀系数较低;随着温度的升高,导电胶的模量与硬度由玻璃态时的较高值降低到高弹态时的较低水平,且银含量较高时的刚度与强度较大;各不匹配热应力分量随温度的变化呈现出"蝌蚪状"或"半蝌蚪状",玻璃态时用于倒装芯片封装的导电胶未发生屈服.%The thermal mechanical analyzer and micro-indentation test system were used to characterize the me-chanical properties of isotropic conductive adhesive (ICA)with different silver contents.Based on numerical simula-tion,the thermal mismatch stress of cured ICA in flip chip packaging was analyzed.The results show that the glass transition temperature of cured ICA with high silver content is relatively higher and the thermal expansion coefficient is lower than those of cured ICA with low silver content.The elastic modulus and hardness of the cured ICA are higher in the glassy state than those in the high-elastic state,and the stiffness and strength are relatively larger for cured ICA with high silver content.On the whole,with the increasing temperature the maximum of thermal stress component increases,then declines rapidly,and decreases slowly,showing a "tadpole shaped"or "semi-tadpole shaped".In the glassy state,the conductive adhesive in flip chip packaging exhibits elasticity.